基于变位分配原理的隧道动态监测控制值研究

Research on Control Value of Tunnel Dynamic Monitoring Based on Displacement Allocation Principle

建立单线和双线隧道开挖有限元模型,分析不同开挖步拱顶沉降变形规律,应用位移释放系数法获取开挖至研究断面不同距离拱顶沉降占总变形比例,基于变位分配原理提出隧道动态监测控制值.结果表明:单线隧道开挖至研究断面前方0.5D、1D、1.5D,拱顶沉降监测以规范规定控制值的80%、90%、95%作为动态控制控制值;双线隧道先行洞和后行洞分别在通过研究断面0.5D、1.0D、2.5D和0.5D、1.0D时,对应选取控制值的70%、80%、90%和75%、90%作为动态控制值.

The finite element model of single line and double line tunnel excavation are established to analyze the settlement deformation law of vault at different excavation steps.The ratio of the settlement of the arch to the total deformation is obtained at different distances from the excavation to the study section by displacement release coefficient method.The control value of tunnel dynamic monitoring is put forward based on the shift allocation principle.The result shows that when the single track tunnel is excavated to the front of the study section,0.5 D,1 Dand 1.5 D,the monitoring of vault settlement should be based on the specification of 80%,90% and 95% of the control value as the dynamic control value;when the first and the second holes of the double track tunnel pass through the study sections 0.5 D,1.0 D,2.5 Dand 0.5 D,and 1.0 Drespectively,70%,80%,90%,and 75% and 90%are selected as dynamic control values corresponding to selected control values.